Reference Channel Research Articles

Near-Range Multipath Mitigation Methodology for Multistatic SAR Applications Using Matched-Adaptive Filters

This article presents a methodology based on matched-adaptive filters, which is used to mitigate the effect of near-range multipath in multistatic SAR systems and transponders. It is challenging to physically construct a bistatic receiver such that the reference signal is not leaked into the received signal, either via coupling in the circuitry or via reflections off objects in the vicinity of the receiver. Due to its much larger amplitude, the reference signal can easily mask near-range targets with its sidelobes. A similar signal degradation is observed in active transponders that are used for calibrating radar systems, when objects exist in their vicinity. In this article, we address these two issues: the coupling between the reference channel and the imaging channel, and the parasitic echoes present in the transponder response. A novel methodology is proposed that is capable of time-domain filtering the undesired components in real time. The novelty consists in combining matched and adaptive filters as a means of boosting performance and resolution estimation, resulting in an extremely accurate multipath elimination method. The proposed methodology is experimentally evaluated and optimized for each of the two aforementioned problems.

Intelligent passive detection of aerial target in space-air-ground integrated networks

Passive detection of moving target is an important part of intelligent surveillance. Satellite has the potential to play a key role in many applications of space-air-ground integrated networks (SAGIN). In this paper, we propose a novel intelligent passive detection method for aerial target based on reservoir computing networks. Specifically, delayed feedback networks are utilized to refine the direct signals from the satellite in the reference channels. In addition, the satellite direct wave interference in the monitoring channels adopts adaptive interference suppression using the minimum mean square error filter. Furthermore, we employ decoupling echo state networks to predict the clutter interference in the monitoring channels and construct the detection statistics accordingly. Finally, a multilayer perceptron is adopted to detect the echo signal after interference suppression. Extensive simulations is conducted to evaluate the performance of our proposed method. Results show that the detection probability is almost 100% when the signal-to-interference ratio of echo signal is −36dB, which demonstrates that our proposed method achieves efficient passive detection for aerial targets in typical SAGIN scenarios.

Compressive Subspace Detectors Based on Sparse Representation in Multistatic Passive Radar Systems

This paper considers the problem of target detection by using compressive observations in a multistatic passive radar system (MS-PRS) consisting of one non-cooperative illuminator of opportunity, one reference channel, and multiple receivers. We first jointly design the measurement matrix for each receiver to obtain the compressive observations, thus making the echo signals at different receivers corresponding to the same target share the same target support indices (SSIs). Following this, a generalized likelihood ratio test (GLRT) based complex-valued compressive subspace detector (CSD) is provided given the prior of receiver noise variance. To further improve the detection performance, we develop a linear-fusion based CSD (LFCSD) by designing a set of weights at the fusion center. For the scenario of unknown noise variance, we continue to derive two GLRT-based unknown-noise CSDs (UNCSD). Specifically, we consider two cases based on whether the noise variance of each receiver is equal, referred to as the UNCSD1 and UNCSD2, respectively. Besides, we provide closed-form expressions of the probability of false alarm and detection of the proposed detectors. It is shown that the proposed UNCSD1 and UNCSD2 have constant false alarm rate (CFAR) properties. Finally, numerical simulation results show that the proposed detectors outperform the generalized coherence correlation (GCC) detector and the energy detector (ED) in low and moderate signal-to-noise ratio (SNR) regions.

A Ferromagnetic Particle Sensor Based on a Honeycomb Permanent Magnet for High Precision and High Throughput

A multi-channel passive ferromagnetic particle inductive sensor is proposed, which is mainly composed of a honeycomb permanent magnet and a set of coils. The honeycomb magnet generates the same high gradient static magnetic field in each channel (a total of 7 channels, 6 surrounding and 1 center), which helps improve the sensor’s throughput while maintain high precision. An induced voltage model that includes most of the structural design parameters is proposed, which provides theoretical support for sensor optimization. The correctness of this model is verified by finite element simulation and experiments. The experimental results show that the detection performance of each channel is almost the same, which is expected to be further improved by setting a reference channel. Moreover, the sensor can detect 70 μm iron particles in a single channel of diameter 4 mm. The proposed sensor can reduce the influence of magnetic field radial uniformity on the induced signals, improve the detection precision, and achieve high throughput (about a 14-fold increase in throughput compared to our previous work). Its high precision and high throughput favor lots of lube oil detection.

Methodology Based on Vector and Scalar Measurement of Traffic Channel Power Levels to Assess Maximum Exposure to Electromagnetic Radiation Generated by 5G NR Systems

Maximum-Power Extrapolation (MPE) for mobile telecommunication sources follows an established paradigm based on the identification and measurement of a channel that acts as a power reference. Prior to the 5G era, the role of reference channel has been played by always-on broadcast signals since they had the great advantage of being always transmitted at the maximum power level allowed for a generic signal channel. However, the beamforming implemented by 5G sources obliges us to rethink this approach. In fact, with beamforming the 5G source can transmit data traffic streams through a beam characterized by a much higher gain than the broadcast one. This implies that the detected power for traffic beams could be much higher than the corresponding power of broadcast beams. In this paper, a novel approach for 5G MPE procedure is presented, where the direct measurement of the received power of a traffic beam is used to assess the maximum exposure generated by a 5G system. An innovative specific experimental setup is also proposed, with the use of a User Equipment (UE) with the aim of forcing the traffic beam toward the measurement positions. In this way, it is possible to directly measure the power of each Resource Element (RE) transmitted by the traffic beam. As opposed to other MPE proposals for 5G, the discussed technique does not require any correction of the measured data since it relies only on the traffic beam pointing toward the measurement position, simplifying the overall MPE procedure and thus reducing the uncertainty of the MPE estimated field strength.

Sensitive and Robust Millimeter-Wave/Terahertz Photonic Crystal Chip for Biosensing Applications

In recent years terahertz (THz) technology has attracted great interest in biosensing applications. Due to the interaction between analyte and electromagnetic (EM) field, a THz resonator is sensitive to changes in the refractive index of the analyte and can be used as a thin-film sensor for rapid pathogen diagnosis. To achieve high sensitivity and reliability, the sensor should have a high Q factor, a high field concentration at the site of the analyte, and the ability to compensate for temperature effects. However, conventional metamaterial methods have a low Q factor, which may lead to ambiguous detection and no attention has been paid to address the temperature effects. Here, we present a photonic crystal (PhC) based chip consisting of a reference channel and a sensing channel with two identical PhC slot resonators. The resonance difference between the resonators is temperature invariant and can be used for analyte detection. The dual-channel PhC chip has a Q factor of 5063 and a figure of merit of 3.1 /RIU/μm (RIU is refractive index unit), which are higher than that of metamaterial sensors. The chip is designed and simulated for the W band by 3D field simulations and is verified by measurements. Our results suggest that THz PhC resonators can provide high sensitivity and high resistance to environmental effects. We anticipate our work to be a starting point for future biosensing applications.

Eye Blink Artefact Removal of Single Frontal EEG Channel Algorithm using Ensemble Empirical Mode Decomposition and Outlier Detection

Recently, the emergence of various applications to use EEG has evolved the EEG device to become wearable with fewer electrodes. Unfortunately, the process of removing artefact becomes challenging since the conventional method requires an additional artefact reference channel or multichannel recording to be working. By focusing on frontal EEG channel recording, this paper proposed an alternative single-channel eye blink artefact removal method based on the ensemble empirical mode decomposition and outlier detection technique. The method removes the segment of the potential eyeblinks artefact on the residual of a pre-determined level of decomposition. An outlier detection technique is introduced to identify the peak of the eyeblink based on the extreme value of the residual signal. The results showed that the corrected EEG signal achieved high correlation, low RMSE and have small differences in PSD when compared to the reference clean EEG. Comparing with an adaptive Wiener filter technique, the corrected EEG signal by the proposed method had better signal-to-artefact ratio.

Cooling performance analysis and structural parameter optimization of X-type truss array channel based on neural networks and genetic algorithm

This study aims to optimize the structural parameters of an innovative cooling channel filled with a novel X-type truss array structure, so as to improve the cooling performance of the mid-chord region of gas turbine blades. In this study, the design of experiment (DOE) for influence parameters of X-type truss array channels was carried out, the variation ranges of influence parameters are as follows: Reynolds number (ReH, 10,000 to 60,000), truss rod diameter ratio (d/H, 0.1 to 0.3), transverse spacing ratio (Xs/C, 0.1 to 0.3) and streamwise spacing ratio (Zs/C, 0.1 to 0.3). The comprehensive effects of each structural parameter and Reynolds number on the flow and heat transfer performance of X-type truss array channels were analyzed. Then the multi-input and multi-output neural network model with prediction deviations less than 3% for the X-type truss array channels was established. Finally, the optimal structure parameters and arrangement of the X-type truss array channels were obtained by optimization design based on the genetic algorithm method, and have been verified by experimental measurement. The results show that the average Nusselt numbers and the friction coefficients of the X-type truss array cooling channel both rise with increasing d/H, drop with increasing Xs/C, and first rise then drop with increasing Zs/C; the comprehensive thermal coefficients first rise and then drop with increasing d/H, Xs/C, and Zs/C. Based on the maximization of average Nusselt number, the optimal values of d/H and Xs/C are 0.3 and 1, the optimal values of Zs/C increase from 1.179 to 2.201, as ReH increases from 10,000 to 60,000. According to the optimization results of maximization of comprehensive thermal coefficient, the optimal values of d/H, Xs/C and Zs/C increase from 0.186 to 0.248, 1.696 to 2.482 and 1.0 to 1.945 respectively with increasing ReH. Compared with the reference channel, the average Nusselt number of the optimized X-type truss array channel increases by 44.50 to 145.49% and the comprehensive thermal coefficient increases by 4.16–9.56% at different Reynolds numbers. The results may provide new ideas for the design of internal cooling structure in future advanced gas turbine blades.

Effectiveness Analysis of the Method of Measuring the Parameters of Network Elements and Signals in the Conditions of Concentrated Interference Spectrum

The measurement method of network elements and communication signals parameters in the conditions of the extraneous signals is developed. The possibility of using adaptive noise compensators in mobile network parameters is considered. In adaptive noise compensators, a reference signal is generated in a reference reception channel without the desired signal. Deleting the desired signal from the reference receiving channel is a problem, especially in a mobile network. In an actual situation, in the mobile network, installing the antenna of the reference channel of the reception in the right way is hardly possible. In addition, the direction of arrival of the reference signal can constantly be changing, which requires adjusting the zero pattern of the antenna of the reference reception channel in the direction of its arrival in real-time. To solve the problem of adaptive interference compensation, it is necessary to find such technical solutions that all these actions for the organization of the reference channel of reception are as simple as possible, formalized, and automated. The work proposes using an elemental adaptive antenna array in the reference receiving channel N. Using mathematical modeling in the MATLAB environment, the efficiency of removing the reference signal from the reference reception channel was analyzed. As a criterion for the effectiveness of the adaptive antenna array in the reference receiving channel, the traditional indicator of spatial-temporal processing, namely the SNR ratio of the reference signal levels to the sum of the levels of interference and noise, is taken. The dependences of the SNR in the reference receiving channel on the interference power level were obtained. The analysis showed that with the help of a 3-element AAA, it is possible to reduce the reference signal level in the reference channel of the adaptive interference compensator by 28 dB. The dependence of the SNR in the reference receiving channel on the number of antenna elements was obtained. The analysis showed that the SNR in the reference receiving channel decreases linearly with an increase in the number of antenna elements. That is, it can be concluded that the more antenna elements the reference receiving channel contains, the more effectively the reference signal is removed in the reference receiving channel of the adaptive interference compensator.

Changes in stream power and morphological adjustments at the event-scale and high spatial resolution along an ephemeral gravel-bed channel

Sediment budgets and morphological channel adjustments are closely related to changes in stream power. In ephemeral channels, whose geomorphic response depends on the magnitude and frequency of hydrological events isolated in time, such relationships are often difficult to establish. This study sought to quantitatively relate morphological adjustments to stream power along different reference channel reaches for the period 2018–2020 in the Azohía Rambla, a Mediterranean gravel-bed ephemeral stream in southeastern Spain. Very high resolution digital terrain models (VHR DTM) (at 1 to 2.5 cm pixel size), combined with ortophotographs and 3D point clouds, generated via SfM photogrammetry and terrestrial laser scanning (TLS) for pre- and post-event stages, together with ground-based surveys were used to estimate the spatial variability of morphological sediment budgets and to assess channel bed mobility and changes in net sediment flux during the study period in two spatial scenarios: reference channel reaches (RCRs) and pilot bed survey areas (PBSAs). The hydraulic variables (flow velocity, Froude number, shear stress, mean stream power and energy gradient, among other) were estimated using a 1D hydrodynamic model calibrated with field information. The high resolution maps allowed a spatially-explicit analysis of stream power and transport efficiency in accordance with the areas of erosion and deposition in each RCR. The incision and bed armoring processes showed different trends according to the stream power (ω), cumulative excess energy (εc), and relative bed stability (RBS). The greatest morphological adjustments at the event scale coincided with ω values above 300 W m−2, εc higher than 3 MJ, and RBS below 0.5. The relationships between the mean stream power gradient at peak flood discharges and the changes in bed elevation verified the bed aggradation (an average surface raising of 0.17 to 0.22 m for δω/δs of −6.2 to −14.5 W m−2 m−1) during the major flood and bed scour (average surface lowering of 0.16 to 0.19 m for δω/δs of 5.8 to 10.6 W m−2 m−1) in the moderated events at the bankfull and sub-bankfull stages. Furthermore, this study contributes new relevant data to the scarce existing literature on the relationships between stream power and morphosedimentary adjustments in a fluvial system highly sensitive and resilient to climate change, as is the case of ephemeral gravel-bed channels.

Identifying Factors That Influence Accuracy of Riparian Vegetation Classification and River Channel Delineation Mapped Using 1 m Data

Riparian vegetation delineation includes both the process of delineating the riparian zone and classifying vegetation within that zone. We developed a holistic framework to assess riparian vegetation delineation that includes evaluating channel boundary delineation accuracy using a combination of pixel- and object-based metrics. We also identified how stream order, riparian zone width, riparian land use, and image shadow influenced the accuracy of delineation and classification. We tested the framework by evaluating vegetation vs. non-vegetation riparian zone maps produced by applying random forest classification to aerial photographs with a 1 m pixel size. We assessed accuracy of the riparian vegetation classification and channel boundary delineation for two rivers in the northeastern United States. Overall accuracy for the channel boundary delineation was generally above 80% for both sites, while object-based accuracy revealed that 50% of delineated channel was less than 5 m away from the reference channel. Stream order affected channel boundary delineation accuracy while land use and image shadows influenced riparian vegetation classification accuracy; riparian zone width had little impact on observed accuracy. The holistic approach to quantification of accuracy that considers both channel boundary delineation and vegetation classification developed in this study provides an important tool to inform riparian management.

A Double-Bridge Channel Shape of a Membraneless Microfluidic Fuel Cell

A double-bridge shape is proposed as a novel flow channel cross-sectional shape of a membraneless microfluidic fuel cell, and its electrochemical performance was analyzed with a numerical model. A membraneless microfluidic fuel cell (MMFC) is a micro/nano-scale fuel cell with better economic and commercial viability with the elimination of the polymer electrolyte membrane. The numerical model involves the Navier–Stokes, Butler–Volmer, and mass transport equations. The results from the numerical model were validated with the experimental results for a single-bridge channel. The proposed MMFC with double-bridge flow channel shape performed better in comparison to the single-bridge channel shape. A parametric study for the double-bridge channel was performed using three sub-channel widths with the fixed total channel width and the bridge height. The performance of the MMFC varied most significantly with the variation in the width of the inner channel among the sub-channel widths, and the power density increased with this channel width because of the reduced width of the mixing layer in the inner channel. The bridge height significantly affected the performance, and at a bridge height at 90% of the channel height, a higher peak power density of 171%was achieved compared to the reference channel.

Unmanned aerial vehicle passive detection for Internet of Space Things

Unmanned aerial vehicle (UAV) passive detection is an essential part of intelligent surveillance in the Internet of Space Things (IoST). The satellite has the potential to play a vital role in many applications of IoST. This paper proposes a novel UAV passive detection using multiple satellites. Specifically, we consider target detection in the ground dual receiver system, which is divided into reference channel and monitoring channel. The reference channel receives the direct wave signals from multiple external emitters, and the monitoring channel receives the echo signals reflected by the UAV. We propose a multiple satellite joint target detection method based on a generalized likelihood ratio test (GLRT). This detection algorithm is robust to the reference channel noise. According to the known or unknown noise variance and interference targets, the conditions are divided into three types, where we use GLRT to design the detectors under different conditions. Extensive simulations are conducted to evaluate the performance of the algorithm under various parameter settings.

Clutter Suppression Method for Off-Grid Effects Mitigation in Airborne Passive Radars with Contaminated Reference Signals.

For an airborne passive radar with contaminated reference signals, the clutter caused by multipath (MP) signals involved in the reference channel (MP clutter) corrupts the covariance estimation in space-time adaptive processing (STAP). In order to overcome the severe STAP performance degradation caused by impure reference signals and off-grid effects, a novel MP clutter suppression method based on local search is proposed for airborne passive radar. In the proposed method, the global dictionary is constructed based on the sparse measurement model of MP clutter, and the global atoms that are most relevant to the residual are selected. Then, the local dictionary is designed iteratively, and local searches are performed to match real MP clutter points. Finally, the off-grid effects are mitigated, and the MP clutter is suppressed from all matched atoms. A range of simulations is conducted in order to demonstrate the effectiveness of the proposed method.

Numerical analysis and optimization on flow and heat transfer performance of a steam-cooled ribbed channel

It aims to enhance the heat transfer performance and reduce the pressure loss of the steam-cooled ribbed channels in the gas turbine blades. Numerical calculations were performed to analyze the flow and heat transfer characteristics in the steam-cooled ribbed channel for different inlet Reynolds number (10,000 ≦ Re ≦ 90,000), rib angle (30° ≦ α ≦ 90°), rib height ratio (0.05 ≦ e/D ≦ 0.15) and rib pitch ratio (0.5 ≦ P/D ≦ 1.5). The flow and heat transfer analysis, response surface analysis, significance analysis and parameter optimization were performed by using the Response Surface Methodology. The results show that the variations of Re, α, e/D and P/D change the size, shape and swirling strength of the secondary flows in different extent, leading to the change of flow and heat transfer characteristics in the steam-cooled ribbed channel. Increasing Re and e/D, and decreasing P/D at the low-medium level of e/D obviously enhance the Nu/Nu0; Decreasing Re and e/D, and increasing P/D result in a reduction in the f/f0. An increment in α first increases and then decreases both the Nu/Nu0 and f/f0. Among the four influence parameters Re, α, e/D and P/D, Re is the most significant parameter affecting the Nu/Nu0, followed by e/D, α and P/D; e/D has the most significant influence on the f/f0, followed by α, Re and P/D. The multi-objective optimization for lower pressure drop and higher heat transfer is achieved at Re of 90,000, α of 41.5152, e/D of 0.1157 and P/D of 0.9747. Compared with the reference channel, the optimized channel has a 86.19% enhancement in heat transfer coefficient and a 38.32% improvement in comprehensive thermal coefficient, at the same Reynolds number (Re = 90,000).

Synthesis of a linear static function for grain moisture meter with capacitive sensors

Moisture content is a grain quality factor, a parameter which changes during the processes of storage and processing and determines consumer properties of different food products. OIML organization in its international recommendation OIML R59 “Moisture Meters for Cereal Grain and Oilseeds” restricts maximal permissible value of moisture meters uncertainty to not more than 3% of relative full scale error. Main task of the research is in receiving linear static function for the grain moisture meter with four capacitive sensors. Method of Least Squares and general linear regression instruments had been used for that purpose. Analyzing the graphs of modified static function for different moist substances it was possible to say that it happened to be far more effective than initial static function and the static function received from a first-order polynomial after the LS method implementation. Root mean estimator was calculated for initial static function, the static function received with the LS method and static function, received after general linear regression implementation as an integral difference between nominal and calculated values of moisture content. Corresponding root mean estimator values were 1.3062%, 1.1616% and 0.4158%, that proves the effectiveness of a static function modified with the general linear regression instruments. Keywords: moisture content measurement; capacitive moisture meter; reference channel; capacitive sensor; linear static function

A Compact Broadband Phase Shifter Based on HMSIW Evanescent Mode

A compact broadband phase shifter based on the half-mode substrate-integrated waveguide (HMSIW) is proposed in this letter. By etching interdigital capacitor or adding blind holes and patches into the HMSIW, the width of the HMSIW can be reduced. Moreover, based on the complementary phase responses of series capacitance and shunt capacitance loading on the HMSIW, a broadband phase shifter is designed with a small phase deviation. To validate the proposed design approach, two phase shift channels and the reference channel are fabricated and measured. Phase shifts of 86° ± 2.5° (and 43.5° ± 2.5°) with fractional bandwidths of 53.3% (and 35.7%) covering central frequencies of 7.5 GHz (and 8.4 GHz) are achieved. The insertion losses of the three channels are 0.76-1.32, 0.40-0.63, and 0.87-1.40 dB, respectively. Besides, the area of each branch is only 0.343λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ; λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> is the guided wavelength at the center frequency in the dielectric.

Discrimination of Bulk and Surface Refractive Index Change in Plasmonic Sensors with Narrow Bandwidth Resonance Combs.

A method to enable surface plasmon resonance (SPR) sensors to discriminate between bulk and surface-localized refractive index changes is demonstrated with modified gold-coated tilted fiber Bragg grating SPR sensors (TFBG-SPR). Without this capability, all high-resolution SPR sensors should be using reference channels and strict temperature control to prevent the contamination of the desired detection of surface-localized chemical or binding events by drift of the refractive index of the medium, in which the experiment is carried out. The very fine comb of high-quality-factor resonances of a TFBG-SPR device coupled to the large differential sensitivity of some of the resonances to various perturbations is used to measure unambiguously the refractive index changes within a surface layer thinner than 25 nm from those of the bulk surrounding. The enabling modification of the conventional TFBG-SPR is a reduction of the gold coating from its optimum value near 50-30 nm: at this lower thickness, a surface plasmon wave can still be excited by a limited number of cladding mode resonances, but at the same time, the metal is thin enough to allow modes away from the SPR to tunnel across the metal and probe the bulk RI value. Measurements and simulations of the deposition of a self-assembled monolayer of 1-dodecanethiol in ethanol show that the bulk refractive index changes as small as 0.0004 can be distinguished from the formation of a 1 nm thick coating on the surface of the fiber.

Estimated ECG Subtraction method for removing ECG artifacts in esophageal recordings of diaphragm EMG

The accuracy of diaphragm electromyogram (EMGdi) derived parameters, as used in critically ill intensive care unit (ICU) patients, can be compromised due to electrocardiographic (ECG) interference in the EMGdi signal. Removal of ECG contamination from the esophageal recordings of the EMGdi is challenging due to spectral overlapping of EMG and ECG signals and because of variability in ECG shape and amplitude. Therefore, we designed an Estimated ECG Subtraction (EES) method, based on three steps: (1) identification of the timing of the ECG artifact without an ECG reference channel, (2) estimation of the normalized ECG, considering the EMGdi as noise, and (3) subtraction of the denormalized ECG estimate from the EMGdi recordings. We evaluated the EES method against the use of a single wavelet-based adaptive filter. Using EMGdi signals of ten ICU patients and simulated contaminated EMG, we demonstrated that the EES method yields uncontaminated EMGdi, and showed that it is more effective than a wavelet-based adaptive filter only. Implementation of this technique may offer means to improve diaphragm activity monitoring and control in clinical practice.

Single-Molecule Tracking of Chromatin-Associated Proteins in the C.elegans Gonad.

Biomolecules are distributed within cells by molecular-scale diffusion and binding events that are invisible in standard fluorescence microscopy. These molecular search kinetics are key to understanding nuclear signaling and chromosome organization and can be directly observed by single-molecule tracking microscopy. Here, we report a method to track individual proteins within intact C.elegans gonads and apply it to study the molecular dynamics of the axis, a proteinaceous backbone that organizes meiotic chromosomes. Using either fluorescent proteins or enzymatically ligated dyes, we obtain multisecond trajectories with a localization precision of 15-25 nm in nuclei actively undergoing meiosis. Correlation with a reference channel allows for accurate measurement of protein dynamics, compensating for movements of the nuclei and chromosomes within the gonad. We find that axis proteins exhibit either static binding to chromatin or free diffusion in the nucleoplasm, and we separately quantify the motion parameters of these distinct populations. Freely diffusing axis proteins selectively explore chromatin-rich regions, suggesting they are circumventing the central phase-separated region of the nucleus. This work demonstrates that single-molecule microscopy can infer nanoscale-resolution dynamics within living tissue, expanding the possible applications of this approach.